A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean
Constraining the thermal evolution of the Arctic Ocean is hampered by notably sparse heat flow measurements and a complex tectonic history. Previous results from the Lomonosov Ridge in the vicinity of the North Pole, and the adjacent central Amundsen Basin reveal varied values, including those highe...
Published in: | Journal of Geodynamics |
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ftoslouniv:oai:www.duo.uio.no:10852/70868 2023-05-15T13:22:41+02:00 A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean ENEngelskEnglishA North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt 2018-09-19T12:43:04Z http://hdl.handle.net/10852/70868 http://urn.nb.no/URN:NBN:no-73989 https://doi.org/10.1016/j.jog.2018.01.017 EN eng http://urn.nb.no/URN:NBN:no-73989 Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt . A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean. Journal of Geodynamics. 2018, 118, 166-181 http://hdl.handle.net/10852/70868 1611011 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal of Geodynamics&rft.volume=118&rft.spage=166&rft.date=2018 Journal of Geodynamics 118 166 181 https://doi.org/10.1016/j.jog.2018.01.017 URN:NBN:no-73989 Fulltext https://www.duo.uio.no/bitstream/handle/10852/70868/2/Shephard_etal_2018_Arctic_heat_flow_JGeod.pdf 0264-3707 Journal article Tidsskriftartikkel SubmittedVersion 2018 ftoslouniv https://doi.org/10.1016/j.jog.2018.01.017 2020-06-21T08:52:35Z Constraining the thermal evolution of the Arctic Ocean is hampered by notably sparse heat flow measurements and a complex tectonic history. Previous results from the Lomonosov Ridge in the vicinity of the North Pole, and the adjacent central Amundsen Basin reveal varied values, including those higher than expected considering plate cooling or simple uniform stretching models. Furthermore, in the vicinity of the North Pole an anomalously slow velocity perturbation exists in upper mantle seismic tomography models. However, whether these observations are related to a thermal anomaly in the mantle remains unknown. We present new heat flow results gathered from 17 sediment cores acquired during the “Arctic Ocean 2016” and “SWERUS-C3” expeditions on the Swedish icebreaker Oden. Three sites located on oceanic lithosphere in the Amundsen Basin between 7°W-71E° reveal surface thermal conductivity of 1.07–1.26 W/mK and heat flow in the order of 71–95 mW/m2, in line-with or slightly higher (1–21 mW/m2) than expected from oceanic heat flow curves. These results contrast with published results from further east in the Amundsen Basin, which indicated surface heat flow values up to 2 times higher than predicted from oceanic crustal cooling models. Heat flow of 49–61 mW/m2 was recovered from the Amerasia Basin. Sites from the submerged continental fragments of the Lomonosov Ridge and Marvin Spur recovered heat flow in the order of 53–76 and 51–69 mW/m2 respectively. When considering the additional potential surface heat flux from radiogenic heat production in the crust, these variable measurements are broadly in line with predictions from uniform extension models for continental crust. A seismically imaged upper mantle velocity anomaly in the central Arctic Ocean may arise from a combination of compositional and thermal variations but requires additional investigation. Disentangling surface heat flow contributions from crustal, lithospheric and mantle processes, including variable along-ridge rifting rates and timing, density and phase changes, conductive and advective dynamics, and regional tectonics, requires further analysis. Article in Journal/Newspaper amundsen basin Arctic Arctic Arctic Ocean Lomonosov Ridge North Pole oden SWERUS-C3 Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic Arctic Ocean North Pole Amerasia Basin ENVELOPE(-170.000,-170.000,80.000,80.000) Marvin Spur ENVELOPE(-110.000,-110.000,86.000,86.000) Amundsen Basin ENVELOPE(74.000,74.000,87.000,87.000) Journal of Geodynamics 118 166 181 |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
English |
description |
Constraining the thermal evolution of the Arctic Ocean is hampered by notably sparse heat flow measurements and a complex tectonic history. Previous results from the Lomonosov Ridge in the vicinity of the North Pole, and the adjacent central Amundsen Basin reveal varied values, including those higher than expected considering plate cooling or simple uniform stretching models. Furthermore, in the vicinity of the North Pole an anomalously slow velocity perturbation exists in upper mantle seismic tomography models. However, whether these observations are related to a thermal anomaly in the mantle remains unknown. We present new heat flow results gathered from 17 sediment cores acquired during the “Arctic Ocean 2016” and “SWERUS-C3” expeditions on the Swedish icebreaker Oden. Three sites located on oceanic lithosphere in the Amundsen Basin between 7°W-71E° reveal surface thermal conductivity of 1.07–1.26 W/mK and heat flow in the order of 71–95 mW/m2, in line-with or slightly higher (1–21 mW/m2) than expected from oceanic heat flow curves. These results contrast with published results from further east in the Amundsen Basin, which indicated surface heat flow values up to 2 times higher than predicted from oceanic crustal cooling models. Heat flow of 49–61 mW/m2 was recovered from the Amerasia Basin. Sites from the submerged continental fragments of the Lomonosov Ridge and Marvin Spur recovered heat flow in the order of 53–76 and 51–69 mW/m2 respectively. When considering the additional potential surface heat flux from radiogenic heat production in the crust, these variable measurements are broadly in line with predictions from uniform extension models for continental crust. A seismically imaged upper mantle velocity anomaly in the central Arctic Ocean may arise from a combination of compositional and thermal variations but requires additional investigation. Disentangling surface heat flow contributions from crustal, lithospheric and mantle processes, including variable along-ridge rifting rates and timing, density and phase changes, conductive and advective dynamics, and regional tectonics, requires further analysis. |
format |
Article in Journal/Newspaper |
author |
Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt |
spellingShingle |
Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
author_facet |
Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt |
author_sort |
Shephard, Grace |
title |
A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
title_short |
A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
title_full |
A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
title_fullStr |
A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
title_full_unstemmed |
A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean |
title_sort |
north pole thermal anomaly? evidence from new and existing heat flow measurements from the central arctic ocean |
publishDate |
2018 |
url |
http://hdl.handle.net/10852/70868 http://urn.nb.no/URN:NBN:no-73989 https://doi.org/10.1016/j.jog.2018.01.017 |
long_lat |
ENVELOPE(-170.000,-170.000,80.000,80.000) ENVELOPE(-110.000,-110.000,86.000,86.000) ENVELOPE(74.000,74.000,87.000,87.000) |
geographic |
Arctic Arctic Ocean North Pole Amerasia Basin Marvin Spur Amundsen Basin |
geographic_facet |
Arctic Arctic Ocean North Pole Amerasia Basin Marvin Spur Amundsen Basin |
genre |
amundsen basin Arctic Arctic Arctic Ocean Lomonosov Ridge North Pole oden SWERUS-C3 |
genre_facet |
amundsen basin Arctic Arctic Arctic Ocean Lomonosov Ridge North Pole oden SWERUS-C3 |
op_source |
0264-3707 |
op_relation |
http://urn.nb.no/URN:NBN:no-73989 Shephard, Grace Wiers, Steffen Bazhenova, Evgenia Perez, Lara F Mejia, Luz Maria Johansson, Carina Jakobsson, Martin O'Regan, Matt . A North Pole thermal anomaly? Evidence from new and existing heat flow measurements from the central Arctic Ocean. Journal of Geodynamics. 2018, 118, 166-181 http://hdl.handle.net/10852/70868 1611011 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal of Geodynamics&rft.volume=118&rft.spage=166&rft.date=2018 Journal of Geodynamics 118 166 181 https://doi.org/10.1016/j.jog.2018.01.017 URN:NBN:no-73989 Fulltext https://www.duo.uio.no/bitstream/handle/10852/70868/2/Shephard_etal_2018_Arctic_heat_flow_JGeod.pdf |
op_doi |
https://doi.org/10.1016/j.jog.2018.01.017 |
container_title |
Journal of Geodynamics |
container_volume |
118 |
container_start_page |
166 |
op_container_end_page |
181 |
_version_ |
1766366250179493888 |